Known security detection devices are used at travel checkpoints to inspect carry-on and/or checked bags for concealed weapons, narcotics, and/or explosives. At least some known security devices utilize X-ray imaging for screening luggage. For example, XDI systems provide an improved discrimination of materials, as compared to that provided by the X-ray baggage scanners, by measuring d-spacings between lattice planes of micro-crystals in materials. A “d-spacing” is a spacing between adjacent layer planes in a crystal.
A checkpoint screening system with XDI using an inverse fan-beam geometry (a large source and a small detector) and a multi-focus x-ray source (MFXS) has been proposed. To reduce the size of the MFXS in such systems, a greater number of detector elements are required. At least one known XDI system includes a secondary collimator defined by an array of slits in a series of high Z (tungsten alloy) baffles. A “high Z” material is a material having a high atomic number, such as, for example, tungsten (Z=74), platinum (Z=78), gold (Z=79), lead (Z=82), and/or uranium (Z=92). However, such a secondary collimator does not permit the number of detector elements to be increased because the baffles cannot be fabricated to include a high number of slits without the operability of the secondary collimator being adversely affected. Moreover, such known secondary collimators are difficult and expensive to manufacture because the collimators are fabricated from tungsten alloy.
Known aluminum composite panel (ACP) is used for advertising signs, external walls, curtain boards, recoating for external walls, roofs, private rooms, internal decoration of sound-insulated rooms, advertising boards, automobile skins, and/or internal and external boat decoration. FIG. 4 shows an exploded perspective view of a known aluminum composite panel (ACP). A conventional ACP sheet 300 includes an inner foam core 302 of EPS with a honeycomb geometry. An aluminum skin 304 is coupled to each length-and-height-wise surface 306 and 308 of foam core 302 with adhesive 310 to form ACP sheet 300.